Emergency electrical control device



June 20, 1950 w. F. EAMES 2,512,315

EMERGENCY ELECTRICAL CONTROL DEVICE Fliled Nov. 28, 1947 7- Circuit 3 u;103 f :IF "w 111 if' ya 99 77 107 I 39 75 f/ )l g l 'L/ i 63a l 109i Q).97

4 a ,10a 95 l F f/ j -79 as 'wlTNEssEs: lNvENToR ATTORNEY Patented June20, 1950 EMERGENCY ELEC TRICAL CONTROL I DEV CE William F. Eames,Westfield, N. J., assigner to Westinghouse Electric Corporation, EastPitts'- burgh, Pa., a corporationI of Pennsylvania Application November28, 1947,. Serial N o. 788,548

11 Claims. l

This invention relates to emergency electrical control devices and ithas particular relation to elevator systems having emergency releasemechanism permitting operation of an elevator independently of safetyinterlocks associated with the elevator.

ln electricall apparatus it is conventional practice in many cases tovprovide safety locks which prevent incorrect or hazardous operation ofthe apparatus. For example in an elevator system, it is conventionalpractice to provide each elevator door or hatchway door with a doorswitch. The door switch has contacts which are open when the associateddoor is open and which are closed when the associated door is closed.The door switches are connected in series for the purpose of preventingoperation of the associated elevator when one or more of the doors areopen. However, under certain emergency conditions, it is desirable topermit operation of the elevator despite the fact that one or more ofthe doors may be open. For this reason, it is the practice to providethe elevator with a manuallye operable emergency release switch forpermit'- ting operation of thev elevator when one or more of the doorsis open.

A conventional emergency release switch may be mounted on an elevatorcar behind a frangible panel. In order to actuate the switch, it isiirst necessary to remove or break the frangible panel. Following suchremoval of the panel, the switch may be actuated to bypass the safetyinterlocks.

The removal of the frangible panel does not interfere with the normaloperation of the conventional elevator system. If thedoors are allclosed, the associated elevator may loe operated in the normal manner.For this reason, when the frangible panel has once been removed ordestroyed, the elevator operator may continue to operate the elevator inthe normal manner without requesting replacement of the frangiblepanel". Such operator' is undesirable;

To illustrate the problem further, let it beV as-A sumed that a lockingdevi-ce for an elevator liatchway door fails mechanically and the doorbounces open as the elevator' car leaves the associated floor. Theopening of the door switch stops the elevator car. However, by operatingthe emergency release switch, the elevator operator can return to thedoor for the purpose of closing the door. Since he may then continue tooperate the elevator car in a normal'` manner', the elevator operatormay neglect tov report the defective door tok his building maintenancedepartment. Consequently, the defective`l door re'-v mainsa source ofdanger to inquisitive or thoughtless persons.

In accordance with the invention an elevator system is provided whereinan emergency release switch is associated' with a frangible panel.However, removal or destruction of the frangible panelJ prevents normaloperation of the elevator system- The elevator can be operated only ifthe eleva-tor operator continuously actuates the emergency releaseswitch. Since such continuous actuation of the switch is' tiresome, theelevator operator soon requests replacement of the frangible panel, andis required by his supervisor to explain the reason for the removal ofthe panel.

It is therefore an object of the invention to provide an improvedemergency release device for electrical systems.

It is a further object of the invention to provide a-n elevator systemwith an emergency release switch wherein a frangible panel must beremoved or destroyedV to actuate the emergency release switch andwherein removal ofthe frangible panel prevents normal operation of theelevator' system.

Other objects of the invention will be apparent from the followingdescription taken in conjunction with the accompanying drawing, inwhichz' Figure 1 is a schematic view of an elevator system embodying theinvention;

Figs. 2 and 3 are schematic views of portions of the system of Fig. lwith parts shown in different conditions of operation, and

Fig. 4 is a view inY sectional elevation of an electrical switch devicesuitable for the system of Fig. 1.

Referring to the drawing, Fig. l shows an elevator car I and acounterweight 3 therefor which are connected by one or more flexiblecables 5 which pass over a sheave 1. The sheave 'l is securedv to ashaft 9 which also carries the armature of a direct-current motor Il anda brake drum I3 having suitable brake shoe mechanism I'5A associatedtherewith.

Forv rotating the shaft 9 the armature ofV thel direct current motor ilis electrically connected across the terminals of the armature of adirect current generator H. This generator armature is secured to ashaft I9 which also carries the rotor of an induction motor 2l and thearmature of a direct current generator 23. rEhe direct currentgenera-tor 23 supplies direct current for energizing the controlcircuits of the elevator system and for energizing the fields oi the gen3 erator I1 and the motor II. Energy for the polyphase motor 2I may bederived from a suitable source of polyphase energy represented by phaseconductors LI, L2 and L3.

Operation of the elevator system is initiated in a conventional mannerby a car switch 25 which is mounted in the elevator car I. (The positionof the switch inthe car is illustrated in dotted lines. For the purposeof depicting connections clearly, the switch is shown removed from thecar.) The car switch initiates energization of suitable elevator controlcircuits 21 for controlling the energization of i'lelds associated withthe generator I1 and the motor II and the enerization of solenoidmechanism for controlling the brake shoe mechanism I5. Sinceanyconventional driving system may be employed for the elevator car I, itis believed that a further description of the system is unnecessary.

As previously pointed out, elevator systems have various interlocks forpreventing undesirableor hazardous operation of the elevator system. Forexample, in Fig. 1 an interlock relay 29 is provided which has asolenoid connected in series with door interlock switches Y forenergization from a suitable source of direct current represented byconductors L4 and L5. Ordinarily, one door interlock switch would beprovided for the elevator car and each hatchway door and the number ofdoors consequently would depend on the specific elevator installation.

, For the purpose of discussion, it will be assumed that the elevatorcar I has four hatchway or corridor doors DI, D2, D3 and D4 which arelocated at the four floors served by the elevator car. Each of theelevator doors carries a contact 3i which engages, a stationary contact33 when the associated door is closed. When the door is opened, in thedirection of the arrow, the contacts separate to open the associatedcircuit. 4 Such door interlock switches are well known in the art. Byinspection of Fig.k l, it will be observed that if any-oi the doorsisopen, the relay 2e cannot be energized to close its contacts.

Ordinarily, the relay 29 would be providedvvith contacts in the variouscar running circuits for the purpose of preventing operation of theelevator system when any of the doors is open. For the purpose ofillustration, it is believed sufcientto indicate one set of contacts 35which are connected in series with the car switch 25. Since the'contacts 35 are, open when the relay 29 is deenergized, it follows thatclosure of the car switch 25 cannot initiate operation of the associatedelevator system unless all of the doors DI, D2, D3 and D4 are closed.

It will be recalled that in emergencies operation of the elevator systemmay be desired despite the fact that one or more of the doors may beopen, To permit such emergency operation, an emergency release device 31is provided which includes a pair of contacts 39 and 4I which areconnected by a bridging contact t3. The contacts 39, 4I and t3 cooperatewith conductors 45 and I1 to bypass the door switches associated withthe doors DI, D2, D3 and D4. (The device 31 is located in the car I asshown in dotted lines. To facilitate illustration of the circuitconnections, the device 31 is shown removed from the car l.)

51. The panel 51 may be constructed of any frangible material which maybe destroyed without damaging associated parts ofthe apparatus. Forexample, porcelain or glass are suitable materials, and glass ordinarilywould be employed for the rangible panel. A hammer (not shown) maybelocatednear the frangible panel to facilitate breakage of the panel byan operator.

If the emergency release switch device 31 com- .prised only the partsthus far speciiically described, destruction or removal of the frangibleI panel 51 would not interfere with the normal 0p- The bridging contactlis is provided with an operating button 49 and has a rod 5I projectingtherefrom to terminate in a head 53. A spring 55 engages the head 53 tourge the button 49 into engagement with a frangible member or paneleration of the elevator system. Consequently, an elevator operator maycontinue to operate his elevator without replacing the irangible panel.

In order to make it impossible to operate the elevator system normallyfollowing removal of the frangible panel 51, the emergency releasedevice 31 is provided with an additional switch for interrupting theinterlocking circuit containing the door switches. The additional switchincludes two contacts 59 and 6I which are connected in series with thedoorfswitches. yA bridging contact t3 normally establishes a connectionbetween the contacts 59 and SI to complete an energizing circuit for therelay 29l when the door switches are closed. The bridging contact 63 maybe biased against the contacts 59, SI or the head 53 by means of aspring 65. It will be understood that an energizing circuit for therelay 29 may be completed through either of two parallel arms. One oithese arms comprises the conductor 45, the contacts 39, 4I and 43 andthe conductor A1. The remaining arm comprises the contacts 59, Si and 53and the door switches.

The system of Fig. 1 represents the normal condition of the emergencyrelease device. In this condition, the door switches are effective forcontrolling the energization of the relay 29.

When emergency operation is desired, the panel 51is removed or broken,as illustrated in Fig. 2. Following breakage of the panel 51, the spring55 forces the button 49 through the position normally occupied by thepanel 51. The resulting movement of the bridging contact 63 by the head53 opens the contacts 59 and 6I. to prevent subsequent energization ofthe relay 29, through the door switches..

Let it be assumedthat the condition necessitating operation of theemergency release switch results from the presence of an open door D4.In order to move the car under such conditions the elevator operatormanually presses the button 4S against the bias ofthe spring 55 to closethe contacts 39 and 4I (Fig). Duringy such movement of the button,the'spring 65 permits suitable adjustment of the bridging contact 63.Since the contacts 39, 4I and 43 now bypass the open door switch of thedoor D4, the relay 29 is energized and the elevator car can be moved asdesired.

By reference to Figj2, it vwill be observed that breakage of the panel51 is accompanied by movement of both of the bridging contacts 43 and 63away from their associated contacts. Consequently, the -elevatoroperator cannot operate the car thereafter' in the normal manner. If hedesires to move the elevator car, he must always press the button 49 toclose atleast one of the associated pairs of contacts. Since this is atiresome act, the .elevator operator soon requests replacement of thepanel 51.

Although the operating mechanism for the emergency release d-e'vice'31illustrated in Figs. 1,

2 and .3 may 'be' employed, ysomcwh atdifferent op,

erating mechanism is illustrated in Fig. 4; In Fig. 4; twocontactsz5'9aand'6|a are shownwhich correspond to the contacts 59 and 6| of Fig. 1.The contacts 59a and Bla are secured by machine screws 1| to a support13' which may be constructed ofV a suitable insulating material,y suchasphenolic resin. The conta-cts 59a and Bla have associated therewith, abridging contact 63a which corresponds to the bridging contact 63 ofFig. l. The bridging contactliSa includes a strip 15 ofvelectroconductive springmaterlal having'at one end a contact 11 forengagement withthe contact 59a and secured atits oppositeend to anelectroconductivearm 19. This' arm vhas 'atongue 8| which extendsthrough an opening inthecontact B'Ia toV permit a pivoting'movement ofthe arm about the opening. A` pin 83'is secured to the contact Slaandextendsthrough the arm119. This pin has a washer' secured to oneend'for thepurpose ofr compressing between the arm 19 and-thel washer aspring 81. By inspection of Fig. 4, it will be observed that the spring81l biases the arm 19 in a direction to urge the con.- tact 11 away fromthe associated contact. 59a. The upper end of the arm 19 is bent to forma protuberance` 89 which operates as a cam follower.

For actuatingl the bridging contact 63a, a cam 9|is secured to a shaft93 which is mounted for rotation relativ-e to the support 13. A' crankarm 95A is secured to the shaft 93 for rotating the shaft and the cam asa unit.

A second bridging contact 43a is providedwhich corresponds to thebridging contact 43 of Fig.v l. The bridging contact 43a is similar inconstruction to the bridging Contact 63a but is spaced therefromV in adirection parallel to the shaft 93. The bridging contact 43a hasassociated therewith contacts which are similar to the. contacts 59a andSla and cooperates with its associated contacts in the same way thatthe.bridging member 63a cooperates with its fixed contacts 59a and Gla. Foractuating the bridging contact 43a against thebias of its spring,a cam91v is secured to the shaft for the purpose of engagingfthe protuberanceor cam. follower 99A of the bridging contactv 43a. 'Ihe support 13. maybek secured to a base member ||l| inany suitable manner, asby means ofmachine screws. |03.

Rotation of the crank arm 95-is eifectedby a plunger |05 which isslidably disposed. in an opening |61 -formed in the-support 13. Thecrank arm 95 carries a pin |01. which enters a slot |09 located in oneend of the` plunger. |05. At its opposite end, theplunger |05 hassecured thereto, a hollow button 49a which corresponds to the button 49of Fig. 1; This button contains a spring which urges the button 49a andits associated plunger to the left relative to the sup.- port 13, asviewed in Fig. 4.

The cams 9| and 91 are shaped'to produce successive operation of thebridging contacts 63a and 43a. With the button in thepositionillustrated in full lines in Fig. 4, the cam 9|` maintains :thebridging contact 63a in bridging relationship relative to its associatedfixed: contacts. The bridging contact 43a, however, does not bridge itsassociated iixed contacts. These positions of the bridging contactscorrespond to the positions of the bridging contacts 63 and 43 in Fig.1.

If the spring Il is permitted to move the button 49a from theintermediate position represented in full lines in Fig. 4 to a positionWherein the end of the button is represented by the broken line H3, theresulting movement of the plunger |05 acting throughthe crank arm 95rotates the shaft 93 in a clockwise direction, as viewed in Fig. 4, torelease the bridging Vcontact 63a. As the cam 9| is moved in a clockwisedirection by rotation of the shaft 93 theV cam releases thecam followerB9 and permits the spring 91 to urge the bridging contact 63a away fromthe fixed contact 59a. The resulting positions of the various parts ofFig. 4 correspond to the positions of the various parts of the device 31in Fig. 2. It will be noted that in this condition, both sets ofcontacts of the emergency release device are open.

Should the elevator operator actuatethe button 49a to the positionwherein the end of the button occupies the position represented by thebroken line H5, the resulting movement of the plunger |05 actuates theshaft 93 in a counterclockwise direction. During the initial rotation ofshaft 93, the cam 9| engages the cam follower 89 to move the bridgingcontact 63a into bridging relationship relative to its associatedcontacts 59a and Ela. The continued rotation of shaft 93 finally bringsthe cam 91 into engagement with its associatedcam follower 99'tomove thebridging contact 43a intobridging relationship relative to itsassociated fixedv contacts. The cams maybe designed to maintain-both ofthe bridging contacts 43a and 63a in-bridging-relationship when the endof the button-occupies the position represented by the broken line H5.The resulting positions ofthe parts correspond to the positions of theparts of the emergency release device 31 illustrated in Fig. 3.

The button 49av is maintained' in its intermediate position by means ofthe member 51; As previously pointed out, the member 57|.4 may take theform of a frangible panel, preferably constructed ofi glass.- The: panel51 is secured to a control panel-P by means of' suitable machine screwsIIT and clipsv H9. It will be understood that the emergencyv releasedevice is located in the elevator car and-that the elevator operatordoes not' have access to the space between the control panelP and the.base. member |0| until he breaks the frangiible panel 5.1.

In operation it will berecalled'that the bridging member 63A wouldl beconnected in` series with the door switches.. Since. this. bridgingcontact is closed when the button 49c1occupies the intermediate ornormal position illustratedin full lines in Fig. 4, it will beappreciated that the elevator operator can operate his `car in a normalmanner by manipulation of the car switch 25 (Fig. l). This assumes thatthe door switches are closed.

Shouldv one of the door switches-be open for any reason, the` elevatoroperator can operate his car by initially-breaking'the frangible panel51f izo-expose the button 49a. Upon destruction of the panel51-,thespring promptly moves the button49atoopen.both of the bridging contacts43afandx63a. Under these -circumstances, the elevaterA operator cannotoperate his car;

rllo-'initiate operation of the car, the elevatoropcratorf-pressesthebutton 49a-to close both of the bridging contacts43a and 63a. This permits operation of the car following closure of thecar switch 25 but such operation is possible only as long as theoperator continues to press the button 49a. Since the continued pressureof the button is tiresome, the operator soon requests replacement of thefrangible panel.

Although the invention has been described with reference to certainspecic embodiments,

numerous modications lfalling within the spirit and scope of theinvention as possible.

Iclaim as my invention: 1 A 1. In an elevator control system, elevatordoor means, a control circuit including interlocking means responsiveto` an opening .operation of the doorv means for interrupting saidcontrol circuit., and a rst switch operable independentlyof the vdoormeans for interrupting the control circuit,

avsecond switch operable for bypassing the interlocking means and thefirst switch, and operating means for the switches, said operating meansbeing operable independently of the dcormeans and being operable from afirst condition wherein both of said switches are open to a. secondcondition wherein the rst switch is eiective :for completing the controlcircuit and wherein the second switch is ineffective for bypassing theinterlocking means and the first switch, said operating 4means beingoperable to a third condition wherein both of the switches are closed. l

2. An elevator control system as dened in claim 1 in combination withmeans urging said operating means towards thenrst condition, andreleasable restraining means for restraining the operating means in thesecond condition.

3. An elevator control system as dened in claim 2 wherein therestraining means comprises a member having a frangible rportieri in thepath of the operating means which may be destroyed readily to releasesaid operating means.

4. In an elevator system, an elevator car having a control panel whichVincludes a' rangible portion, a control unit comprising an operatingmember separated from the interior of the elevator car by said frangibleportion, biasing means yieldably urging said operating member into anintermediate position wherein the operating member engages the frangibleportion, said biasingy means being effective upon removal of thefrangible portion for urging the operating member through the positionnormally occupied by the frangible portion towards a released position,said operating member being movable against its bias away from theirangible portion towards an actuated position', said control unitincluding a rst switch and a second switch responsive to the positionofthe operating member, an elevatordoor including a third switchresponsive to the position of the door, a control circuit including saidi'lrst and third switches in series, the iirst switch being closed inthe intermediate position of the operating member and open in thereleased position of the operating member, said second switch being openin the released and intermediate positions of the operating member andclosed in theactuated position of the operating member, and meanscontrolled by the second switch for bypassing the first and thirdswitches.

5. In an electrical switch device, iirst switch means, second switchmeans, operating means for the switch means including an operatingmember operable from a i'irst position wherein bothof the switch meansare open, to a second position wherein only one of the switch means isopen, said operatingmember beingoperable to a third position whereinboth of the switch means are closed, 'means yieldably urging vtheoperating member towards the first position, and releasable restrainingmeans restraining said operating member in the second position, saidreleasable restraining means being releasable for permitting operationof said operating member between said three positions.l

6. An electrical switch device as defined in claim 5 wherein thereleasable restraining means comprises a frangible member, saidfrangible member being readily breakable without damage to the remainderof the switch device to release the operating member.

'7. In an electrical device, a circuit having connected in parallel anormally-closed rst arm and a normally-open second arm, a frangiblemember, control means responsive to removal of the frangible member forinterrupting the normallyclosed arm, said control means includingmanually operable means accessible only following removal of thefrangible member for closing the normally-open arm, and yieldablebiasing means for urging the manually operable means to the conditionwherein thev second arm is open.

8. In an elevator system, a door control circuit having rst and secondarms connected in parallel, a rst switch and a door-operated secondswitch connected in the first arm, a manuallyoperated third switchconnected in the second arm, said switches having open and closedconditions, biasing means urging the rst and third switches intopredetermined first conditions, and releasable retaining means forreleasably retaining the first switch in a second condition under normalconditions of'operation of the elevator system.

9. A system as claimed in claim 8, wherein the rst switch and secondswitchv are connected in series in the iirst arm, and the releasableretaining means comprises a frangible glass panel nornally retaining therst switch in closed condiion.

10. A system as claimed in claim 8, wherein the glass panel until brokenprevents operation of the third switch.

11. A switch assembly comprising first and second switches having openconditions and closed conditions, said switches being biased towardsopen positions, and means including a frangible member preventing accessto said switches for changing their conditions, said frangible memberbeing positioned to retain the iirst switch in closed position until thefrangible member is removed from its normal position. i

WILLIAM F. EAMES.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS

